Three years after the death of Border Patrol Agent Brian Terry -- a tragedy which exposed and ultimately ended Operation Fast and Furious -- the public is finally getting a glimpse into Terry's final moments.

Federal court records released Tuesday provide the first official account of the firefight along the Arizona-Mexico border that killed Terry in December 2010. Among other details, they reveal two of four federal agents at the scene that day actually fired bean bags -- not bullets -- at a violent drug gang carrying assault rifles. Weapons from the botched anti-gun trafficking program were found at Terry's murder scene.

Such an account was not available until now, with both the FBI and Department of Homeland Security never releasing an incident report and Terry's fellow agents under a gag order.

But as part of the court fight over the sentencing of admitted killer Manuel Osorio-Arellanes, prosecutors released first-hand accounts from three fellow agents involved in the shooting. Those agents, members of BORTAC, an elite unit within the Border Patrol, had deployed in the desert to locate a drug gang, known as a rip crew, that had terrorized the Nogales, Ariz., area for months.

The rip crew's job was to stop and steal the drug loads of competing smugglers. They also terrorized and assaulted human smugglers and otherwise innocent illegal immigrants trying to enter the U.S. Terry's specially trained team was specifically deployed in the desert to stop them.

Documents show that on Dec. 14, 2010, Terry's team was on a hill above a ravine. A ground sensor went off alerting them to the approaching smugglers. When agents yelled "police" in Spanish, the smugglers turned and fired. According to the documents, this happened at 11:08 p.m. Just 52 minutes later, Terry would have been relieved by a second BORTAC team and gone home for Christmas.

"I saw some members of the group point their weapons at us," Agent Gabriel Fragoza declared to the court. "Agent Castano and I deployed less lethal bean bag rounds as the individuals began to shoot at us. I saw muzzle flashes coming from the individuals, then heard Agent Terry say 'I'm hit! I'm hit! I can't feel my legs'."

Agent William Castano gave a similar account, saying, "I heard shooting which was coming from the wash. I heard Agent Terry say 'I'm hit.' I went to Agent Terry to administer first aid. At this time, he said, 'I can't feel my legs. I'm paralyzed.' Agent Terry soon lost consciousness and died at the scene."

Robert Heyer, Terry's cousin, told Fox News that few details have been released from that day.

"The court documents released in the last two days have given us some indication of what took place but I think the family really wants to really see and walk the ground in the area in question of where Brian died. We're hoping that will give them better understanding and closure in Brian's death," Heyer said.

Of the five-member rip crew, three are in custody and two remain at large. Manuel Osorio-Arellanes pleaded guilty to felony murder -- though he did not actually fire the bullet that killed Terry. Arrellanes had 51 rounds and an assault rifle when caught. That weapon and one additional AK-47 were found at the scene.

Under federal sentencing guidelines, Arellanes is set to get life in prison, though in a plea bargain the U.S. attorney is asking for 30 years.

The court records leave two unanswered questions. First, it is unclear who stashed Fast and Furious weapons in the desert. Second, it is unclear how the agents were so outgunned.

There's a principle in police work known as "plus one" -- which effectively holds that law enforcement should be better armed than the suspects they're pursuing. Confronting assault weapon-armed gang members in the desert with bean bags would seem to violate that principle.

The Border Patrol has said in the past that Terry's unit had the "freedom" to put down their bean bags and use other weapons, but chose not to. However, other Border Patrol agents say policy guidelines and the rules of engagement for BORTAC that night encouraged the agents to use non-lethal force first.